A list from tauzero's website (used to be NASA's Breakthrough Propulsion Labs) the site is herehttp://www.tauzero.aero
you can Google these papers and find most of them on the web if you're interested.
I am particularly interested in Tajmar's work which involves graviton and acceleration fields and may lead to "star trek" like effects in under 50 years.
Benford, James (2008) “Space Applications of High Power Microwaves”, IEEE Trans. on Plasma Sci., V.36, pg. 569.
Benford, James; and Benford, Gregory (2003) “Flight of Microwave-Driven Sails: Experiments and Applications”, Beamed Energy Propulsion, AIP Conf. Proc. 664, pg. 303, A. Pakhomov, ed.
Bennett, Gary; Forward, R.L; and Frisbee, R.H. (1995) Report on the NASA/JPL Workshop on Advanced Quantum/Relativity Theory Propulsion", AIAA 95-2599, 31st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 10-12 July 1995, San Diego, California.
Brin, David, (1983). "The 'Great Silence': the Controversy Concerning Extraterrestrial Intelligent Life" Quarterly Journal of the Royal Astronomical Society, v.24, pp283-309 <http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1983QJRAS..24..283B>
Cassenti, Brice, N. (2008) “Design Considerations for the Interstellar Ramjet”. Paper AIAA-2008-4797 presented at the 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Hartford, Connecticut, July 20-23.
Cassenti, Brice, N. (1993) "Design Concepts for the Interstellar Ramjet", Journal of the British Interplanetary Society, Vol. 46, pp. 151-160.
Cassenti, Brice, N. (1982) "Design Considerations for Relativistic Antimatter Rockets", Journal of the British Interplanetary Society, Vol. 35, pp. 396-404.
Cassenti, Brice, N. (1982) "A Comparison of Interstellar Propulsion Systems", Journal of the British Interplanetary Society, Vol. 35, pp. 116-124.
Cramer, John; Forward, R.L; Morris, Michael: Visser, Matt: Benford Greg: and Landis, Geoff (1995) "Natural wormholes as gravitational lenses" Physical Review D, Vol. 51, No. 6, pp. 3117-3120.
Kare, Jordin, (2002) High-acceleration Micro-scale Laser Sails for Interstellar Propulsion, Final Report, NIAC Research Grant #07600-070
31 December 2001 (Revised 15 Feb. 2002) <http://www.niac.usra.edu/files/studies/final_report/597Kare.pdf>
Landis, Geoffrey A. (2004) "Interstellar Flight by Particle Beam," Acta Astronautica. Vol 55, No. 11, 931-934.
LaPointe, M. R. (2001), "Antimatter Production at a Potential Boundary", AIAA-01-3361, presented at the AIAA 37th Joint Propulsion Conference, Salt Lake City, UT, July 8-11, 2001.
LaPointe, M. R.(1991) "Antiproton Powered Propulsion with Magnetically Confined Plasma Engines", Journal of Propulsion and Power, Vol.7 No.5, pp. 749-759.
Long, Kelvin, (2007). The Status of the warp drive (& collected papers). Journal British Interplanetary Society. Special edition dedicated to warp drive. Vol.59, No 5/6.
Maccone, Claudio, (2008), "The Statistical Drake Equation", Paper IAC-08-A4.1.4, presented at the 2008 International Astronautical Congress held in Glasgow, Scotland, UK
Maccone, Claudio, (2002) The Sun as a Gravitational Lens: Proposed Space Missions, International Academy of Astronautics (IAA)
(first published in 1997 with two later editions in 1999 and 2002).
Maccone, Claudio, (1994) Telecommunications, KLT and Relativity by IPI Press, Colorado Springs, USA.
Matloff,Gregory L; Les Johnson, Les; Bangs ,C. (2007) Living Off the Land in Space: Green Roads to the Cosmos, Springer.
Millis, M. G. (1997) "Challenge to Create the Space Drive", AIAA Journal of Propulsion and Power, Vol. 13, N. 5, pp. 577-582.
Tajmar, M; Plesescu, F; and Seifert, B. (2008) "Anomalous Fiber Optic Gyroscope Signals Observed above Spinning Rings at Low Temperature", Journal of Physics: Conference Proceedings, 25th Low Temperature Physics Conference, 2008